Manufacture of rubberlike polymerization products



Patented June 6, 1939 PATENT" OFFICE MANUFACTURE OF RUBBERLIKE POLYMERIZATION PRODUCTS Bernard James Habgood, Rowland Hill, and Leslie Budworth Morgan, Blackley, .Manchester, England, assignors to Imperial Chemical Industries Limited, a corporation of Great Britain No Drawing. Application June 3, 1937, Serial No. 146,312. In Great Britain June. 4, 1936 16 Claims.

This invention relates to synthetic rubber-like materials.

' The "objector this invention is to produce new synthetic rubber-like materials. A further ob ject is to provide methods of manufacturing new synthetic rubber-like materials. ,A further object is to produce new compounded products of these new synthetic rubber-like materials. A further object is to provide methods of compounding such new synthetic rubber-like materials to give new products.- Further objects will appear hereinafter.

These Objects are accomplished by the following invention. We have found that we can make new synthetic materials possessing valuable nib- 'ber-like properties, by the process which comprises interpolymerizing in aqueous emulsion a mixture of butadiene with not more than half its weight of a methacrylic ester of the formula 20 (RH: (I)

- cm=oc-oomomo-R wherein R stands for, either an alkyl radical acid'with the corresponding monoaryl ethers of ethylene glycol.

While amounts of methacrylic ester up to onehalf that of the butadiene may be employed :as] already stated, amounts of between 25 and 40% of the butadiene give the products in which the 40 rubber-like properties are the most pronounced.

The aqueous emulsion for polymerization may be obtained, for example, by passing the requisite quantity of butadiene gas or cooled buta-' diene liquid into a mixture of water or ice, and the ester, and other necessary ingredients in aclosed vessel, and agitating. The emulsification and interpolymerization can be conveniently ef- Iected in what may be regarded as a single technical operation, if the ingredientsof the mixture are emulsified by agitating at the te p rature at which interpolymerization is to beeflected, and agitation then continued sufllciently long for the necessary interpolymerization process to take pla'ceJ Suitable emulsifying agents are salts of bases :of'high molecular weight and organic or The inorganic acids, such as diethylaminoethyloleylamide acetate or hydrochloride, cetyltrimethylammonium methyl sulphate, dimethylcetylsulphonium. methyl sulphate and cetylpiperidinium methyl sulphate.

Small proportions of one or more suitable electrolytes, e. g. acetic acid or acetic acid admixed with sodium acetate, maybe conveniently vincluded in the mixtures. Small proportions of substances yielding oxygen, e. g. hydrogen perox- 10 ide, and of chlorinated hydrocarbons, e. g. carbon tetrachloride may be alsoincluded as catalysts. The aforementioned substances have the general effect of either increasing the total yield of' rubber-like'product, or of increasing the rate 15 of its formation, or both, and they may in addition, improve the physical properties of the product.

The interpolymerization products are produced in latex-like form. They may be obtained in massive form by coagulating the latex, separating the coa-gulum, washing and. drying. The coagulation may be effected by adding ethyl alcohol to the latex or by using one of the other processes already known for this purpose. 25 Washing and drying may be effected on heated rollers, provided with a wate'r-spray device.

The interpolymerizationproducts may be mixed with compounding ingredients including carbon blacks, and vulcanized to give .products resembling vulcanized natural rubber and having excellent mechanical and physical properties,'and the invention includes'this compounding and vulcanizing. In general, these, synthetic rubber-like materials, after washing and drying, 5

are obtained in the form. of elastic sheets, resembling crepe rubber, which can be compounded in' a manner similar tothat employed with natural rubber on standard rubber processing machinery. The materials after compounding with carbon black and-vulcanizing give products which closely resemble vulcanized natural rubber, but have certain advantages, such as increased resistance to heat, light, and certain solvents such as pyridine. Natural rubber 4 or other synthetic rubber-like materials may be used in conjunction with the interpol'ymerization products; I

The following examples, in which the parts are by weight, illustrate but do not limit the ina vention.

Examp e 1.-30 parts of butadiene, 15 parts 2 are mixed together and the mixture agitated for days at 60 C. The resulting latex-like product is coagulated by the addition of ethyl alcohol. The coagulum is separated, washed free I from soluble salts on a roller mill, provided with a spray and then dried. A rubber-like product is obtained in nearly quantitative yield.

The product is compounded as follows:

- Parts Interpolymerization product 100 Channel black 50 Stearic a 2 Zinc oxide Tricresyl phosp 20 Sulphur 2 -Mercaptoben2b-thiazol 1 This compounded stock after vulcanizing for 1 hour at 141 C. gives a snappy rubber which, when tested .by the Shore'Elastometer, shows a hardness of '70? and an *elasticity of 68%.

Example 2.40 parts of butadiene, 14 parts of p-methoxyethyl methacrylate, 60 parts of a 2% aqueous solution of trimethylcetylammonium methyl sulphate and 3.5 parts of 6% acetic acid are mixed together and heated at 60 C.

with agitation for 5 days and the interpolymerization'product then isolated as in Example 1.

The product is obtained in almost quantitative yield, and is similar to that of 'Example 1.

:After compounding and vulcanizing as described in Example 1, a very similar product is obtained.

Example 3.--100 parts of p-ethoxyethyl methacrylate, 216 parts of butadiene, 600 parts of -a 2% aqueous solution of diethylaminoethyloleylamide acetate, 35 parts of 6% acetic acid, 80 partsof carbon tetrachloride and 30 parts of 0.6% hydrogen peroxide are mixed together and heated up to 60 C. with agitation for 1 day,

and the interpolymerization product isolated as in Example 1. The product is obtained in about The material after vulcanizing for 1 hour at 14 C; gives a rubber-like product. having a hardness of 65 and an elasticity of 64%.

Example 4.-- 14 parts of p-ethoxyethyl methacrylate, -30 parts of'butadiene, 60 parts of a 2% aqueous solution of diethylaminoethyloleylamide acetate; 3.5 parts of 6% acetic acid and 8 parts 'of carbon tetrachloride are mixed to gether and heated'at'60" -C(with agitation for four and a half dayspand the product then iso-. lated as in Example 1; The yield is almost quantitative. a I

The product is. compounded as in Example 3 and after vulcanizing for 1' hour'at 141 C. gives a rubber-like product'of hardness 71, elasticity 57% and "a tensile strength at break ,of 178 kgjcm.

' Example 5.'-'l3 parts'of pemethoxyethyl'meth acrylate,-28' parts of butadiene. 60 parts of; a-

2% aqueous solution of trimethylcetylammon um methyl sulphate, 3.5 partsof 6% acetic acid,

, -and'8 parts 1of-carbon tetrachloride are mixed and emulsification; interpolymeriiation and isolation eifected as in Example 3. almost obtained.

theoretical yield of polymerization product is After compounding and vulcanizing as in Example 3 a rubber-like product is obtained having a .hardness of 72, an elasticity of 58% and a tensile strength at break of 187 kg./cm.

Example 6.-- parts of B-phenoxyethyl methacrylate,.a new compound, B. P. 152-6 C./13 mm. made by esterifying methacrylic acid with ethylene glycol monophenylether, 35 parts of butadiene, 60 parts of a 2% aqueous solution of trimethylcetylammonium methyl sulphate, and

3.5 parts of 6% acetic acid, are mixed and emulsification, interpolymeri'zation and isolation effected as in Example 3, except that the polymerization treatment is extended to 7 days.

After compounding and vulcanizing as in Example 3 a rubber-like product is obtained having a hardness of 80 and an elasticity of 46%. When compounded andvulcanized according to Example 1 a more elastic product is obtained.

This invention is a valuable advance in the art, as it extends the range of known rubber substitutes, giving new substitutes for rubber which have in many respects advantages over rubber.

As many apparently widely different embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that we do not limit ourselves to the specific embodiments thereof 'except as defined in the appended claims.

'We' claim:

1. Process" for the manufacture of new synthetic rubber-like materials, which comprises interpolymerizing in aqueous emulsion a mixture of butadiene with not more than half its weight ofa methacrylic ester of the formula cHio wherein R stands for a hydrocarbon radical of the group consisting of alkyl radicals containing less than 5 carbon atoms, phenyl radicals, tolyl radicals, and xylyl radicals.

2. Process as claimed in claim 1, in which a small proportion of acetic acid is added to the -mixture prior to theinterpolymerization.

3. Process as claimed in claim 1, in which the aqueous emulsion contains an emulsifying agent which is a salt of an organic base of high molec ular weight.

4. Process as claimed in claim 1 in which dimethylaminoethyloleylamide acetate is present in the aqueous emulsion.

5; Process as claimed in claim lin which trimethylcetylamm'onium methyl sulfate is present v in the aqueous emulsion.

6. Process as claimed in claim l yin which a a small proportion of a substance lyi'elding oxygen is employed as a catalyst.

7; Process as .claimed in claim 1 in which v interpolymerization is assisted by adding a chlorinated hydrocarbon solvent to the mixture.

8- A Synthetic rubber-like material obtained by the process of claim 1.

9. Process which comprises compounding and tained by the process of claim 1.

10. As new products,, synthetic rubber-like materials obtained bythe process of-ciaim 1 'vulcanizing a synthetic rubber-like material obv which have been thereafter compounded'and 1.1- The process of claim 1 further charactert terpolymerizing a mixture of butadiene with about Mi of its weight of 'betamethoxyethyl quaternary ammonium salts.

I about half its weight of betaethoxyethylmeth- 13. Process forthe manufacture of new syn thetic rubber-like materials which comprises interpolymerizing a mixture of butadiene with acrylate while the two are emulsified in a quantity of a 2% aqueous solution of trimethylcetyh ammonium methyl sulfate equal to about twice the weight of the butadiene, said emulsion also containing a quantity of 6% acetic acid equal to about 11 of the weight of the butadiene, said interpolymerization being continued for about five days at about 60 C. with agitation of the dispersion and thereafter separating, washing,

and drying the coagulum.

14. Process for the manufacture of new syn-- thetic rubber-like materials which comprises inmethacrylate while the two are emulsified in a quantity of a 2% aqueous solution of trimethylcetylammonium methyl sulfate equal to about 2% times the weight of the butadiene, said emulsion also containing a quantity of 6% acetic acid equal to about 12 7 of the weight of the butadiene and a quantity of .carbon tetrachloride equal to about the weight of the butadiene and said interpolymerization being continued for one day at about 60 C. with-agitation of the dispersion and thereafter separating, washing, and drying the coagulum.

15, Process as claimedin claim 1 in which the methacrylic ester is betamethoxyethyl mathacrylate.

I 16. Process as claimed in claim 1 in which the methacrylic ester is betaethoxyethyl methacrylate. v BERNARD JAMES HABGOOD.

ROWLAND HILL.

LESLIE BUDWORTH MORGAN. 

